rfc1443.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

                           by the retrieval were it to exist. However,
                           the agent does not have sufficient
                           information to provide a value, and until a
                           value is provided, the conceptual row may not
                           be made available for use by the managed
                           device.  For those columns to which the agent
                           provides read-create access, the
                           'noSuchInstance' exception tells the
                           management station that it must issue
                           additional management protocol set
                           operations, in order to provide a value
                           associated with this column.

                           - the exception 'noSuchObject' is returned,
                           indicating that the agent does not implement
                           the object-type associated with this column
                           or that there is no conceptual row for which
                           this column would be accessible in the MIB
                           view used by the retrieval.  As such, the
                           management station can not issue any
                           management protocol set operations to create





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          RFC 1443        Textual Conventions for SNMPv2      April 1993


                           an instance of this column.

                      If the value associated with the status column is
                      'notReady', then the management station must first
                      deal with all 'noSuchInstance' columns, if any.
                      Having done so, the value of the status column
                      becomes 'notInService', and we proceed to
                      interaction 4.

                      Interaction 4: Making the Conceptual Row Available

                      Once the management station is satisfied with the
                      values associated with the columns of the
                      conceptual row, it issues a management protocol
                      set operation to set the status column to
                      'active'.  If the agent has sufficient information
                      to make the conceptual row available for use by
                      the managed device, the management protocol set
                      operation succeeds (a 'noError' response is
                      returned).  Otherwise, the management protocol set
                      operation fails with an error of
                      'inconsistentValue'.

                                          NOTE WELL

                           A conceptual row having a status column with
                           value 'notInService' or 'notReady' is
                           unavailable to the managed device.  As such,
                           it is possible for the managed device to
                           create its own instances during the time
                           between the management protocol set operation
                           which sets the status column to
                           'createAndWait' and the management protocol
                           set operation which sets the status column to
                           'active'.  In this case, when the management
                           protocol set operation is issued to set the
                           status column to 'active', the values held in
                           the agent supersede those used by the managed
                           device.

                      If the management station is prevented from
                      setting the status column to 'active' (e.g., due
                      to management station or network failure) the
                      conceptual row will be left in the 'notInService'
                      or 'notReady' state, consuming resources





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          RFC 1443        Textual Conventions for SNMPv2      April 1993


                      indefinitely.  The agent must detect conceptual
                      rows that have been in either state for an
                      abnormally long period of time and remove them.
                      This period of time should be long enough to allow
                      for human response time (including 'think time')
                      between the creation of the conceptual row and the
                      setting of the status to 'active'.  It is
                      suggested that this period be approximately 5
                      minutes in length.


                                  Conceptual Row Suspension

                      When a conceptual row is 'active', the management
                      station may issue a management protocol set
                      operation which sets the instance of the status
                      column to 'notInService'.  If the agent is
                      unwilling to do so, the set operation fails with
                      an error of 'wrongValue'.  Otherwise, the
                      conceptual row is taken out of service, and a
                      'noError' response is returned.  It is the
                      responsibility of the the DESCRIPTION clause of
                      the status column to indicate under what
                      circumstances the status column should be taken
                      out of service (e.g., in order for the value of
                      some other column of the same conceptual row to be
                      modified).


                                   Conceptual Row Deletion

                      For deletion of conceptual rows, a management
                      protocol set operation is issued which sets the
                      instance of the status column to 'destroy'.  This
                      request may be made regardless of the current
                      value of the status column (e.g., it is possible
                      to delete conceptual rows which are either
                      'notReady', 'notInService' or 'active'.) If the
                      operation succeeds, then all instances associated
                      with the conceptual row are immediately removed."










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          RFC 1443        Textual Conventions for SNMPv2      April 1993


              SYNTAX       INTEGER {
                               -- the following two values are states:
                               -- these values may be read or written
                               active(1),
                               notInService(2),

                               -- the following value is a state:
                               -- this value may be read, but not written
                               notReady(3),

                               -- the following three values are
                               -- actions: these values may be written,
                               --   but are never read
                               createAndGo(4),
                               createAndWait(5),
                               destroy(6)
                           }

































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          RFC 1443        Textual Conventions for SNMPv2      April 1993


          TimeStamp ::= TEXTUAL-CONVENTION
              STATUS       current
              DESCRIPTION
                      "The value of MIB-II's sysUpTime object at which a
                      specific occurrence happened.  The specific
                      occurrence must be defined in the description of
                      any object defined using this type."
              SYNTAX       TimeTicks


          TimeInterval ::= TEXTUAL-CONVENTION
              STATUS       current
              DESCRIPTION
                      "A period of time, measured in units of 0.01
                      seconds."
              SYNTAX       INTEGER (0..2147483647)


































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          RFC 1443        Textual Conventions for SNMPv2      April 1993


          DateAndTime ::= TEXTUAL-CONVENTION
              DISPLAY-HINT "2d-1d-1d,1d:1d:1d.1d,1a1d:1d"
              STATUS       current
              DESCRIPTION
                      "A date-time specification.

                      field  octets  contents                  range
                      -----  ------  --------                  -----
                        1      1-2   year                      0..65536
                        2       3    month                     1..12
                        3       4    day                       1..31
                        4       5    hour                      0..23
                        5       6    minutes                   0..59
                        6       7    seconds                   0..60
                                     (use 60 for leap-second)
                        7       8    deci-seconds              0..9
                        8       9    direction from UTC        '+' / '-'
                        9      10    hours from UTC            0..11
                       10      11    minutes from UTC          0..59

                      For example, Tuesday May 26, 1992 at 1:30:15 PM
                      EDT would be displayed as:

                                  1992-5-26,13:30:15.0,-4:0

                      Note that if only local time is known, then
                      timezone information (fields 8-10) is not
                      present."
              SYNTAX       OCTET STRING (SIZE (8 | 11))


          END


















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          RFC 1443        Textual Conventions for SNMPv2      April 1993


          3.  Mapping of the TEXTUAL-CONVENTION macro

          The TEXTUAL-CONVENTION macro is used to convey the syntax and
          semantics associated with a textual convention.  It should be
          noted that the expansion of the TEXTUAL-CONVENTION macro is
          something which conceptually happens during implementation and
          not during run-time.

          For all descriptors appearing in an information module, the
          descriptor shall be unique and mnemonic, and shall not exceed
          64 characters in length.  Further, the hyphen is not allowed
          as a character in the name of any textual convention.


          3.1.  Mapping of the DISPLAY-HINT clause

          The DISPLAY-HINT clause, which need not be present, gives a
          hint as to how the value of an instance of an object with the
          syntax defined using this textual convention might be
          displayed.  The DISPLAY-HINT clause may only be present when
          the syntax has an underlying primitive type of INTEGER or
          OCTET STRING.

          When the syntax has an underlying primitive type of INTEGER,
          the hint consists of a single character suggesting a display
          format, either: 'x' for hexadecimal, 'd' for decimal, or 'o'
          for octal, or 'b' for binary.

          When the syntax has an underlying primitive type of OCTET
          STRING, the hint consists of one or more octet-format
          specifications.  Each specification consists of five parts,
          with each part using and removing zero or more of the next
          octets from the value and producing the next zero or more
          characters to be displayed.  The octets within the value are
          processed in order of significance, most significant first.

          The five parts of a octet-format specification are:

          (1)  the (optional) repeat indicator; if present, this part is
               a '*', and indicates that the current octet of the value
               is to be used as the repeat count.  The repeat count is
               an unsigned integer (which may be zero) which specifies
               how many times the remainder of this octet-format
               specification should be successively applied.  If the
               repeat indicator is not present, the repeat count is one.





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          RFC 1443        Textual Conventions for SNMPv2      April 1993


          (2)  the octet length: one or more decimal digits specifying
               the number of octets of the value to be used and
               formatted by this octet-specification.  Note that the
               octet length can be zero.  If less than this number of
               octets remain in the value, then the lesser number of
               octets are used.

          (3)  the display format, either: 'x' for hexadecimal, 'd' for
               decimal, 'o' for octal, or 'a' for ascii.  If the octet
               length part is greater than one, and the display format
               part refers to a numeric format, then network-byte
               ordering (big-endian encoding) is used interpreting the
               octets in the value.

          (4)  the (optional) display separator character; if present,
               this part is a single character which is produced for
               display after each application of this octet-
               specification; however, this character is not produced
               for display if it would be immediately followed by the
               display of the repeat terminator character for this
               octet-specification.  This character can be any character
               other than a decimal digit and a '*'.

          (5)  the (optional) repeat terminator character, which can be
               present only if the display separator character is
               present and this octet-specification begins with a repeat
               indicator; if present, this part is a single character
               which is produced after all the zero or more repeated
               applications (as given by the repeat count) of this
               octet-specification.  This character can be any character
               other than a decimal digit and a '*'.

          Output of a display separator character or a repeat terminator
          character is suppressed if it would occur as the last
          character of the display.

          If the octets of the value are exhausted before all the
          octet-format specification have been used, then the excess
          specifications are ignored.  If additional octets remain in
          the value after interpreting all the octet-format
          specifications, then the last octet-format specification is
          re-interpreted to process the additional octets, until no
          octets remain in the value.







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          RFC 1443        Textual Conventions for SNMPv2      April 1993


          3.2.  Mapping of the STATUS clause

          The STATUS clause, which must be present, indicates whether
          this definition is current or historic.

          The values "current", and "obsolete" are self-explanatory.
          The "deprecated" value indicates that the textual convention
          is obsolete, but that an implementor may wish to support that
          object to foster interoperability with older implementations.